Summary/Abstract American Indian/Alaska Natives (AI/ANs) are one of the most at-risk racial/ethnic groups in the United States for adverse cardiometabolic (CM) and behavior health (BH) outcomes, including cardiovascular disease (CVD), diabetes, obesogenic behaviors and alcohol and other drug (AOD) use problems. Urban AI/ANs constitute over two-thirds of the total AI/AN population and represent a highly disenfranchised and marginalized population who may be at particular risk for CM and BH problems, but they have been significantly under-represented in health studies. Adolescence is a critical developmental period for understanding the emergence of CM and BH problems in vulnerable populations, as behavioral health risk factors often begin in adolescence and early onset of CM dysregulation and BH problems can set the stage for widening health disparities that continue long into adulthood. Sleep is an important but understudied risk factor that may contribute to CM and BH problems in adolescents, but no prior studies have investigated the role of sleep in contributing to health disparities in urban AI/AN youth. The current proposal builds on our team?s extensive experience conducting research with urban AI/AN youth and provides a comprehensive, mixed method approach to investigate the role of sleep disturbances in contributing to health behaviors and clinically relevant health outcomes in a culturally sensitive, community-informed, and integrated framework. Specifically, this project incorporates a longitudinal assessment of objectively and subjectively measured sleep, multiple dimensions of BH problems, including tobacco, caffeine, and alcohol and other drug use, physical inactivity and electronic media use, measured CM risk factors, and qualitative methods to better understand the social and cultural context of sleep in urban AI/AN youth and the influence on downstream BH and CM problems. Outcomes from this work will address several key knowledge gaps, which are crucial to better understand pervasive health disparities among urban AI/AN youth, to identify which youth are most at risk, and to inform a future novel and culturally- sensitive intervention within this underserved community.